(a) The equations given below represent the different stages of Nitrogen Cycle in plants.
(i) `2NH_(3)^(+)+3O_(2)overset([A])rarr 2NO_(2)^(-)+2H^(+)+2H_(2)O`
(ii) `2NO_(2)^(-)+O_(2)overset([B])rarr 2NO_(3)^(-)`
(iii) `underset("[Nitrate]")(NO_(3)^(-))overset([C])rarr underset("[Molecular Nitrogen]")(N_(2))`
In the above equations [A], [B],[C] indicate the bacteria which is responsible for the reaction. Name them.
(b) Define Denitrification.
(c) Which enzyme is required for Nitrogen fixation ?

Explanation

(a) (i) A - Nitrosomonas
(ii) B - Nitrobacter
(iii) C- Pseudomonas
(b) Denitrification : Nitrates in the soil are converted back into atmospheric nitrogen by a process called denitrification. Bacteria involved in this process are Pseudomonas, Thiobacillus and Bacillus subtilis.
`"Nitrate"overset("Pseudomonas")rarr "Molecular Nitrogen"`
(c) Enzyme required for Nitrogen fixation : Nitrate Reductase, Nitrite Reductase